The DNA Sequencing Shared Resource was established at AECCC in 1992 and has grown rapidly since that time. In 1995, the facility was moved to a new location and since then the number of samples sequenced annually has increased from 6000 to 24000. Genotyping has been added to the services provided and the facility is now in the process of converting operations to the ABI3700 capillary electrophoresis platform with a capacity to sequence at least 384 samples/day. Dr. Kucherlapati?s mouse genome sequencing group has already acquired significant expertise with the ABI3700 since the acquisition of the first unit in October 1999 and three additional units in April 2000 so that a smooth transition in the AECCC facility is expected. For those investigators who require the sequence of one or a few BACs from any organism of interest, a service is planned that will generate shotgun sequencing of plasmids or M13 phage DNA and assembly. The change to the capillary electrophoresis systems will allow enhanced genomic sequencing service by the ABI 377 systems, one for genotyping of human samples and the other for genotyping of mouse samples. It is expected that at least 1800-2700 genotypes per ABI377 unit will be possible/day. Since the last CCSG review the quality of sequencing services has continued to improve and the facility has consistently ranked among the top sequencing units in the nation based upon audits performed by the Association of Biomolecular Resource Facilities. In the 1999 study, AECCC ranked as number one in sequencing both standard and difficult-to-sequence templates. The facility provides consultation services and protocols to AECCC investigators for designing sequencing strategies and for the preparation of substrates. Methods to obtain optimal sequence are provided through protocol manuals and consultation. A variety of sequence assembly services are provided, in particular programs designed by Dr. P. Green (University of Washington) that are run on a UNIX platform with the assistance of facility staff. Optimal base-calling service is also provided. To insure that AECCC investigators are provided with the most modern methods of sequence analysis and annotation, an individual with a strong bioinformatics background is being recruited to provide this service. During the past funding period this facility provided a bulk oligonucleotide purchasing service; this will now be provided by the College.